Support DISTINCT queries on dictionary

[gauravbordoloi]

Support DISTINCT queries on dictionary

[gauravbordoloi]

Hi @ironage
Understood and yeah the other table will work for me. Thank you. You can close the issue.

[ironage]

Hi @gauravbordoloi we don't currently support sorting or distinct on a collection. What do you expect the behaviour of distinct to be, given dictionaries with the following sets of keys: {a, b, c}, {a, b}, {c}? When talking about comparing collections, we usually need to specify the match behaviour: ANY/ALL/NONE. So then we might be looking for syntax like DISTINCT(ALL attributes)? Is that the feature you are looking for?

[gauravbordoloi]

Hi @ironage , I have multiple data like these,

[
    {
        "name": "Levis Shirt",
        "attributes": {
            "color": "White",
            "size": "XL"
        }
    },
    {
        "name": "Nike Shirt",
        "attributes": {
            "color": "Red",
            "size": "L"
        }
    },
    {
        "name": "Adidas Shirt",
        "attributes": {
            "color": "Black",
            "size": "XXL"
        }
    }
]

What I want to do is

1. fetch all the attribute keys without duplicates - Result (color, size)
2. fetch all the attribute values for a particular key without duplicates- Result (color=White,Red,Black)

2nd point, I am able to get the data using the query
//attr = "color"
realm.objects(ProductModel).filtered(`status == $0 DISTINCT(attributes['${attr}'])`, "PUBLISH")

but for the 1st point, nothing is working. I tried the below code but it doesn't work
realm.objects(ProductModel).filtered(`status == $0 DISTINCT([email protected]`, "PUBLISH")

[ironage]

@gauravbordoloi we don't currently support the query you are trying to do. Fundamentally, our query system produces matching objects, not a collection of matching properties. I think what you want is an advanced use of projections.
A solution for you today would be to also insert your keys into an independent class that tracks unique keys. So every time you insert into the attribute dictionary, you could also call
realm.create("AllKeys", {_id: "myKey"}, UpdateMode.Modified); // UpdateMode.Modified makes this an upsert
Insertion/lookup is fast because a primary key is indexed. Then to get all keys, you iterate over all objects of this class
realm.objects("AllKeys");
Would this work for you?